Asus P8Z68-V-LE memory problem.

Hi, I just purchased the above said mothorboard and ran into some problems, I hope you guys would help me.

1> I purchased 2 sticks of transcend ram, each of 2 gigs which were not in the compatibility list of that mobo (I saw that thing later, after I ordered the rams)

Now, When I put my both rams in first and second slot(non, dual channel config) , my pc runs fine, rams get detected and I get full 4 gb to use.
But when I connect the ram in dual channel config or in first and last slot(not a dual channel, is it) my system starts, the memok light remains red and I get no display.

Should I buy another compatible ram ? or can this be solved?

2>Also, I have a cable having HDMI male port to one end and DVI-D male port to one end, and I am planning to purchase a LED monitor with HD. Can this cable help me? how? and, also can you please suggest me a good monitor upto 23inch?

thanks in advance!